Three years ago the original "Unholy Union" came about and documented Elmoreman's adaption of Suzuki DR650 forks onto a R80G/S, following an example by Crankshaft who adapted Honda CR250 forks onto his R80G/S.

Elmoreman's thread showed the way and fellow members bgoodsoil and Hardwaregrrl (who now has the WP 50's as of Feb 2012) and Beater to name a few have tasted the yellow kool-aid and followed this path.

For me, the ideal front end needed to be conventional for the aesthetics, have adjustable compression and rebound damping and be European... nothing against the adapters of the alternative non-Euro sources... but defiling and R80G/S is one thing and putting Japanese parts onto it is a whole different and perhaps a bit edgy proposition than I wanted to take.

Early investigations showed that famous BMW tuners HPN use Marzocchi Magnum conventions in the 50mm size that do have adjustable comp and rebound.

I picked up a set of Magnum 50mm's, my local suspension tuner told me these had two significant negatives one was that the comp and rebound worked in such as way it has no effect for the first 1/3 of the stroke, and two the sliders were too soft and tended to destroy themselves, this he said would be a significant issue on a large bike like a G/S.

While I didn't take any pictures, when I stripped the forks to clean and inspect them I found that the oil looked like melted aluminum. Clearly Magnum's weren't the forks for me.

This left one choice.... from 1997 (or 1998) until 2000 KTM used WP Extreme 50mm conventional forks. Some more digging on the internet showed that many riders consider these to be the best conventional forks ever built.

Having this information I again headed to the internet for Inspiration:

Here's my original inspiration who did this before the others below, CrazyIvan HPN conversion with 50mm Marzocchi Magnums:

Option 3A that was used by Roadsacallin and Jay.T was to use the plans from R-Dubb's thread to have custom triples made... I believe something like 10 sets were made R-Dubb using three and others going to ADVR's... there are some rumblings of someone else running a few sets and I have my name down for one! These do require a custom stem made and for those choosing this path I can suggest Banke Performance in California who used to make custom triples for $125 or so...

***2012 edit***... you'll see later in this thread that HPMGuy did a second run and pushed out ~12 more sets, as of Feb '12 is is ramping up to do a third run. Look for the HPMGuy triple thread in the vendors forum.

Initially I was going to choose path number one, and run stock KTM triples with a spacer, but when I was recently in the Belgium I happened to run into CrazyIvan who passed on to me the KTM lower triple with the custom BMW stem, as well as the swing arm below... but that is for another thread...

One note on the WP Extreme forks, while these were used for all KTM's from 125cc up to the 640 Adventures, only the ADventures ran a 300mm diameter front rotor... I believe the fork lower that thread onto the slider has a unique caliper holder on the 640's. For the smaller cc bikes you can source larger discs elsewhere but most are 260mm or 280mm or smaller... there are also "supermoto" kits with rotors as large as 320mm, but there there may be issues with these and 21" wheels, I also hear that 4-piston caliper conversions conflict with the 21" wheels due to spoke/caliper spacing... again, more later on this.

Simply put, if you want to run a 300mm rotor, get the forks from a 640.

Here's my starting point, a new Braking USA 300mm rotor is on the way and I am searching for a stock 640 caliper now

For those going this way, here is a link to a great downloadable color WP Extreme tech manual LINK

.

hardwaregrrl

04-09-2011 05:07 PM

Hey SOLO....link isn't working. I'm curious if you will be doing the frame bracing, if nothing else, at least the steering head? I apologize if you've already mentioned this. Looking forward to results!!!:lurk

Solo Lobo

04-09-2011 05:29 PM

Quote:

Originally Posted by hardwaregrrl
(Post 15629331)

Hey SOLO....link isn't working. I'm curious if you will be doing the frame bracing, if nothing else, at least the steering head? I apologize if you've already mentioned this. Looking forward to results!!!:lurk

Hi Jenna,

Which link?

Frame bracing will come perhaps next winter.. for now I plan on adapting the forks with the travel shortened a bit for this summer. This winter I will tackle the swing arm and frame... still waiting to hear if Brad ever got ahold of Paul Rooney....

Foot dragger

04-09-2011 05:35 PM

Ive used these forks on an Lc4 620,best forks Ive tried for stock forks,plush and took high speed desert hits amazingly well. Ive thought of putting a set on my DR.

hardwaregrrl

04-09-2011 05:58 PM

Quote:

Originally Posted by SOLO LOBO
(Post 15629464)

Hi Jenna,

Which link?

sorry, the manual for the extremes.

fishkens

04-09-2011 05:59 PM

Quote:

Originally Posted by SOLO LOBO
(Post 15629098)

.. but that is for another thread...

Oh my, this is like watching someone open your christmas present, one...

piece

of

tape

at

a

time.

:lol3:lol3:lol3

Padmei

04-09-2011 05:59 PM

You're a legend Solo for starting the thread with history, reasons & details:clap

I take it most of this knowledge can be transferred to whichever forks/ front end you choose as the only difference would be fork diameter & height? Using the new triples, the offset would be the same no matter what type of fork used to achieve the original BMW turning circle?

Solo Lobo

04-09-2011 06:18 PM

Quote:

Originally Posted by hardwaregrrl
(Post 15629666)

sorry, the manual for the extremes.

Fixed! thanks for letting me know!

Beater

04-09-2011 07:39 PM

I am all for the engineering it takes to put those massive forks on it ... custom triples and all. But ... DRZ400 forks are a bolt on swap ... Just saying (and they're 49mm)

(I'm also quite sure that the WP forks are are a large upgrade in quality ... But I don't know ... )